Ask a great inventor to invent, and that's exactly what he'll do. Sometimes the ideas pop out like cannon bursts: "consider this ... " or "maybe this?" or "Wait! How about THIS!"

Ben Franklin did that with balloons.

In the 1780s, Franklin was America's ambassador to France, living in Paris, where all over town, people were experimenting with balloon flight. They'd constructed car-sized baskets, packed in bottles of champagne, iced lemonade, added packets of roast duck sandwiches, set up in a public park, fired up the gas, inflated big balloons and soared off — floating over the town, waving, doing acrobatics, getting in trouble, snagging onto roofs, having near misses. Everybody could see them. Everybody talked about them. Europe was having its first wave of "Ballomania," writes historian Richard Holmes. Balloons were the 18th century's version of space travel, our first leap into the sky.

But they couldn't be directed. The first "aerialists" would just fly up and go wherever the wind blew. Balloons weren't like horses or boats. You couldn't use them to get somewhere. So what, really, were they good for, asked Sir Joseph Banks, president of the Royal Society in London. Anything useful? Anything practical?

That's where Franklin jumped in. "Practical" was his territory. His mind wandered freely, and he liked to solve problems. So here, culled from Franklin's letters, are his Balloon Ideas, many of them proposed to Sir Joseph, as reported by Richard Holmes.

Need to send a message to a neighbor? You have a footman? Good. All you do is attach him to a hydrogen balloon, which will make him much lighter, (says Holmes quoting Franklin,) "so his body weight was reduced to 'perhaps 8 or 10 Pounds,' " and so made capable of running in a straight line in leaps and bounds "across Countries as fast as the Wind, and over Hedges, Ditches & even Water ... " Bingo! You've just created the 18th century version of an instant message!

I don't know why Franklin called it an "elbow" chair, but here's the gist. You are at a fair. Imagine lots and lots of people stuck on the ground looking for something to do. But look up. There's an easy chair hooked to a flock of balloons, parked in the sky, with a great view of a village, town, meadow, whatever. The plan? You pull the chair down to the ground, invite the tourist to sit and then winch "the picturesque spectator 'a mile high for a Guinea' to see the view." A revenue earner — like the Eiffel Tower without the tower.

Holmes describes it as "Franklin's patent balloon icebox." This being an era before refrigeration, imagine someone with five ducks, freshly killed. Rather than eat them right away, the hunter would like to store them, but where? Well, the higher you go, the cooler it gets, so, thought Dr. Franklin, why not create a container in the sky? "People will keep such Globes anchored in the Air, to which by Pullies they may draw up Game to be preserved in the Cool, & Water to be frozen when Ice is wanted." The Original Frigidaire.

When Franklin moved back to Philadelphia in 1785, he had trouble walking. He'd developed a bad case of gout. To get to the Philadelphia State Assembly on working days, he arranged to be "lifted by four stout assistants" on a sedan chair. This apparently embarrassed him, because he suggested harnessing his sedan to small hydrogen balloon "sufficiently large to raise me from the ground." This, he thought, would make him so much lighter he imagined himself floating, "being led by a string held by one man walking on the ground." (Richard Holmes calculated that a single balloon, ten feet across, containing one thousand cubic feet of hydrogen, would have done what Franklin imagined. But it doesn't seem they ever tried it.)

Not To Mention ...

He had other ideas. I've skipped over the obvious ones, using balloons to transport infantry across rivers and channels, to predict the weather, for military intelligence. He was one of those guys that if you gave him a problem, he'd think it over, and out would pour a crazy stream of stories, get-rich-quick schemes, fairy tales, adventures and solutions to problems you'd never known you had. He had what you might call "a mind wide-open" ready, like those balloons, to fly anywhere ...

Richard Holmes' forthcoming book on ballooning (to be released in America next fall) is calledFalling Upwards: How We Took To The Air. If you'd like to imagine flying over Paris carried by a gaggle of balloons, here's the classic short French film The Red Balloon, (The whole thing! It's not too long.) in which a host of balloons rescue a little boy from some bullies and pull him up into the sky to take him ... well, I'm not sure where they're going. Maybe to balloon heaven. Directed by Albert Lamorisse, this film won both an Oscar and the Palm d'Or for short films at Cannes in 1956 and it gives me just a hint, perhaps a more heart-rending hint, of what Franklin saw sailing overhead in the 1780s.